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Message ID: 902     Entry time: Fri Apr 6 01:36:39 2012
Author: Tara, Frank 
Type: Summary 
Category: NoiseBudget 
Subject: ACAV loop changes 

summary of all changes made and more detailed plots will be posted soon, so check back later

writing in progress

  • replaced New Focus power supply for RFPD with Agilent power supply (+/-15V)
  • added isolation transformer between mixer LO and main splitter of 14.75MHz LO
  • changed gain of input stage from PDH-box from 10 to 20
  • replaced thickfilm resistors in input stage with thin film ones
  • added offset potentiometer to input opamp
  • added 25MHz HP-filter to AOM driver/amplfier

ACAV loop is now completely free from line harmonics and the in-loop level dropped to ~10nV/rtHz (includes 7nV/rtHz from analyzer). Mixer dark noise is ~25nV/rtHz.

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